CHAPTER IX. 



MECHANICAL PHILOSOPHY. 



Mechanical philosophy treats of the equilibrium and motion 

 of bodies: its great object of inquiry is, into the causes which 

 produce or prevent motion, and the manner in which it takes 

 place. " That part of mechanics which relates to the action of - 

 forces producing equilibrium or rest, in bodies, is called statics; 

 that which relates to the action of forces producing motion is 

 called dynamics" 



The practical value of this branch of science consists in the 

 application of a few simple mechanical powers, either single or 

 combined in some kind of machinery, in overcoming resistances, 

 and producing and applying motion to useful purposes. 



" Power is the means by which a machine is moved and 

 force attained ; thus we have horse power, water power, steam 

 power, <fec. 



Force is the means by which bodies are set in motion, kept 

 in motion, and when moving are brought to rest The force 

 of gunpowder sets a ball in motion and keeps it moving until 

 the resisting force of the air, and the force of gravity bring it 

 to rest" 



A few simple instruments or machines variously combined, 

 produce all the complicated, powerful and beautiful pieces of 

 machinery which have ever been constructed. 



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